Protractor for pipe bending machines



July 2, 1946. N WHLUNGHAM' zmmm PROTRAC'IOR FOR PIPE BENDING MACHINESFiled Feb. 24', 1944 FITTURNEY Patented July 2, 1946 PROTRACTOR FOR PIPEBENDING MACHINES Elijah N. Willingharn, Santa Rosa, Calif.

Application February 24, 1944, Serial No. 523,759

1 Claim. 1

This invention relates to improvements in protractors for pipe bendingmachines.

The principal object of this invention is to provide a protractor fordetermining the degree of bend for a pipe being bent in a standard pipebending machine.

A further object is to produce a device of this character which may beattached to any standard pipe bending machine.

A further object is to produce a device of this character which issimple in construction, cheap to manufacture and easy to apply to anymachine.

A further object is to produce a device of this character which may bereadily adjusted and one wherein the parts may not be readily deranged.

Other objects and advantages will be apparent during the course of thefollowing description.

In the accompanying drawing forming a part of this specification and inwhich like numerals are employed to designate like parts throughout thesame,

Fig. I is a top plan view of my device as the same appears in use.

Fig. II is a view similar to I showing the device after a ninety degreebend has been made, and

Fig. III is a cross sectional view taken on the line 3-3 of Fig. II.

In bending pipe the pipe is usually held in a pipe bending machine whichcomprises a forming die and holding jaw and a movable jaw, the movablejaw being power driven, and as it moves along the outside of the pipe,it bends the pipe around the forming die, the result being that the pipeis bent to any desired degree or angle.

' Heretofore it has been necessary to stop the machine and use straightedges, angles, etc, to try to determine the degrees to which the pipehas been bent. This was a very difficul't operation and consumedconsiderable time There is also inherent in the pipe certain resiliency,so that when the machine stops the pipe springs back a few degrees, anditis then necessary to bend it a few more degrees, in order to come upto the desired degree of bend.

Applicant has devised a .protractor-like arrangement, which may beattached to the top of the standard machine, which prom-actor has an armcarrying a roller which engages the side of the pipe and by setting theprotractor at a zero point and then bending the pipe the exact degree ofbend can be readily determined; also, the degree of over-bend to takecare of the springback can also be determined, which enables the user toproduce bend after bend of exactly the 2 same number of degrees. This isparticularly important in ship construction work where complicated bendsof a definite number of degrees must be made.

In the accompanying drawing wherein for the purpose of illustration isshown a preferred embodiment of my invention, the numeral 5 designatesthe base of a machine which supports the forming die 6 upon a stub shaft'1. The pipe 8 is held against the forming die by a holding jaw 9.

A movable jaw is shown at l I, which moves in the path shown by thearrow A.

The parts thus far described are common to all bending machines.

My inventioncomprises a protractor I2, which is secured to the shaft 6by a bolt l3, and an arm !4, rotatable about the stub-shaft l andsupported upon a collar l6, resting upon the top of the forming die 6.The arm M carries a pointer II which moves over a scale formed on theprotractor l2. A roller 28 is slideably mounted on the arm M, and isadapted to lie against the side of the pipe 8.

The result of this construction is that when the pipe is positioned inthe machine, as shown in Fig. I and the roller it is brought against theside of the pipe, bolt 13 is loosened and the protractor is rotateduntil it registers zero with the pointer ll; then the bolt I3 is locked.

The machine is now started so that the movable jaw moves in thedirection of the arrow A and causes the pipe to be bent around theforming die 6. The roller ill will be forced around from a position inFig. I to that in Fig. II, when a ninety degree bend is being made, andthe operator can then watch the pointer until it has arrived at theninety degree mark or a predetermined numbered degrees beyond to takecare of the springiness in the pipe.

As the roller always bears the same relation to the pipe, it isimmaterial Where the roller is positioned against the pipe as long asthe pointer and the zero degree marl: are set when the operation firstcommences.

It will thus be seen that I have provided a device which will performall the objects above set forth and one which is positive in determiningthe amount of bend of a pipe being worked upon.

It is to be understood that the form of my invention herewith shown anddescribed is to be taken as a preferred example of the same and thatvarious changes relative to the material, size, shape and arrangement ofparts may be resorted to without departing from the spirit of theinvention or the scope of the subjoined claim.

engaging said pipe and adapted to bend a portion of said pipe about saiddie and an arm carried by said protractor, said arm having a rollerengaging the side of said pipe next to said die and at a point alwaystangent to the face of said forming die projected from a point where themovable jaw faces the die.

ELIJAH N. WILLINGHAM.

